Switch for drilling machines



Sept. 9, 1930.` H. RCHANDLER SWITCH FOR DRILLING MACHINES Filed April 25, 1925 13.17 4 A\ 2 Z al uw /2 0 3 8 5 H z W Ptented'sept. 9, 19,30"v l r Il v V/ t 'HoivmRnci-IANDLER, on MANSFIELD;.oHIqnssIGNoR To oHfio :BR-Ass coMrnNY; t .or MANsFELn, onrofAlconronATIoN oF NEWJERsn-.Y i

Y :SWITCH Fon immune MAcnInns Y nppudnouciefiiiprn 25, 1925. -seriai 253.3719."

` invention relates toan electric 4switch In the drawingcf Ag l y i and `its `application `to an :electrically V oper- Fig. 1 isv a iriew representing a drilling atedfrnacliineand hasparticularreference machine of the lhandcontrolled type and lto ft manualjtypeof machine, that yis, one shows the application of my switch Iriechaisghgld" and controlled by the operator. nisni theretofand 'itsrelationl to the `drilling 55 lTheobject of niyfinyentionis toprovidea mechanisinanditlieoperator-`"` 3 `switch tol controlthey flowV of` currentto an i fFiigzQis a sectional `View "of-the switch y `electrically-operated machine suohfthat the .portion of niyinventionshown `in an open fswifiltchrnay be openedfor closed manually at position.

i l'aO'thf ill'of theoperator ,or openedautomati- Y FigQB is a Vieiif'rofthe svtitchl'mG Cir y s cally if the` operator not able jto control portiono'f iny invention, butlin'a closed poi -gthe manipulation ofthe inachine. v `sition Las is the case When current is flowing "ThefsW-itchportion `of"my!invention is tothe mechanis1n.

particularly adapted ,for use inconnection The switch portion oiV my invention `corn-` t- ""lo withWhatlarelusually terrned electrically-op prises a member l, preferably ofjnietal, and 65 eratedhanddrills, that is,` drills lhaving an Whilel have shown it of an elbowffomation, Y y i 'electrically controlled niechanismfor rotat it 4Inay `beeither straight -or l otherwise as ingithe drill"-` point,` butnthewdrill, asysuch, `may be required. One end of the member` Y held. and'inanipulated by thefoperator. `isjinternally :threaded at Aone end, as inf7 0 In the caselof such drills', Vitis usual `for an Y dicatedby the threads 2, andto these ,threads '70 operator Ito desire toicailisef-the drill to Jcut is securedanneinber `preferably ofimetal v u "a'sirajpidly as possible'andj,undeifsch con- 'and Which is "in turn secured to the machine" `ditions"`thediillfpoint isQlilrely ltI jstiokand TheV nielnber Sais `protected `by atnbe 4 causethe stalling ofthe IIiechahisnroperating lof insulating materialwhich Inaybefof` the i i "thej` il`rillwandV this inftufrnf3-rnaydamagetheb#vulcanizediiberor phenolic compoimdcon-` 75` rlimec'hanisin'or itmay be' dangerousftolthe struction. Y Y A t operator offthedrill if theoperating mecha- `To the opposite end ofltheineniber 1I y i fof considerablepower as'it maybe `provide projectingflange 5` which is` pro thefcase of a' drill andfcaus'e theinechanism vided With a thread 6 andgtothis threaded l A B0 :to 'instantlystarttorotatefif the drill point collar 5 is threadablysecnreda metal tnbey'. S0` Ysuddenly stojsrotating due toits sticking. Thernctaltube Z'is protected on theioiitside f These'conditions usually, happen when the byf an linsulating` tube Srsiinilarto thetube Y y operato t "notv onfhisjguardjaswould be 4 and-nthe inside is protected by `an inithe casefitheisforcfing theldrilling, and lit sulatingl tube"9 which is counterbored to, t l-mayhappen dueyytolthejdrill pointsuddenly 'nform a; recess lO and shoulder 111@ ler-l `S5 k striking` seineI unusually hard; substance manently lnounted Within the recess l0 and l Which'was not anticipatedby the operatorf batting against" the `v shoulder 11 is a; metal l I have arranged `a switch tobeused in liningjlZ; Slida'bly `mounted Within the" fcombinat-ion ttitli"tliejclass' ofIdrillingmechametal lining "l2 is` a metal plungerlfwhich "11.40 nisrn referredyto orfwith such other m`a has"permanentlyfsecured therein acarbon 90 chinesvastheswitch inaylb applicable-to "elenieiitll' "jflheinsulating tube `9 "ispro- Wherebyrthe 1Vciiri'entwill be instantly 'cnt off i vided Withjanotlierjfchamber 15a-and this from the, operating Vmechanismshould y: thef chamberis closed attheendbytheinsulating` mechanisnijbe"stalled,tendingtorotatethe member 16 `'which isthreadalcly` secured in f Q45 mgghajqigmfutof'fgrglpgitinf f `position by means-of the coloperating threads 95 Myinyentionli'eidesinthe f ewfandnovel 17, Mounted withinfthe chamber lfis a i construction?cornbixiaftion andgrelatiori fof tspringl under compression when theswitch thevario'usparts'hereininore fullydes'cribed is inanflopen'positionfasshownfin EigifQ. .l i -andidisc'losedi in the drawngfaccornp "ying The meniber p13 isprOVidedWith `a'recess in f 50 Mthisislpecication. which ismseciired,preferablybysolderilrgg;the` 10Q y PATENT member. The cables 23 and 27 7, 3 and 9. Positioned within end of the conductor of the insulated cable 19.

The flange 5 is counter-bored to perinanently receive an insulating cup-shaped meinber 20. In the member is mounted a metal member 21 in which in turn is mounted a cai'- bon member 22 to be engaged by the carbon member 14 when the switch is closed, as shown in Fig. 3. Secured to the member 21, preferably by soldering, is the insulated cable 23.

The insulating and metal tubes 3 and 4 are provided with an opening 24 through which passes an insulating cable 25. The cables 23 and 25 extend through the interior passage 26 of the tube 23 and to the electrically operating mechanism in the machine M. The cable 19 has formed a. loop 27. The loop 27 is maintained by clamping means 28 which may consist of binding wire, tape or a clamping are bound together, as indicated at 29, for convenience, and the terminals 23 and 27 are connected to the source of power. ln order to maintain the switch in'an open position there is secured to the exterior ot the insulating tube 8 a metal hand or clamp 30, which may be Jforced into position Vand held there by friction or which may be secured thereto by a binding screw similar to that used in a hose clamp, and projecting from the band 30 is a projecting member 31 v,which has a screw `cap 32 and a recess termed within the member 31. The recess in the member 31 is positioned over an opening extending' through the side of the members the recess in the member 31 and projecting through the last said opening is an insulating plug 33 which is'held in an advanced position by means ot the spring 34. Secured to the insulating plug 33 and projecting outwardly beyond the cap 32 is a handle 35 by means of which the insulating plug 33 may be drawn outwardly at the will of the operator. When the plug 33 is drawn outwardly through the medium of the handle 35 the spring 18 will advance the member 13 so that the carbon nember 14 will engage with the carbon member 22 thereby closing the switch and coinpleting the circuit from the source of power to the machine M. It will be noted that the switch cannot be opened by manipulation of the handle 35.

Assuming that the switch S is secured to the drilling mechanism M through the inedium oi' the insulating` tube 4 and its reinforcing metal tube 3,'the members 3 and 4 will constitute a handle for one of the operators hands and the oppositely .disposed` end secured to the drilling mechanism M is another projecting handle 3G tobe grasped by the other hand of the operator. The operator will grasp the handles 4 and 36 and place his toot through the loop 27, Yassuming a relative position with respectto the mechanism M, as shown iiiFig. 1f. To start the drilloperating,

he will pull out the handle 35 which will permit carbon contacts 14 and 22 to engage thereby closing thc circuit to the drill M. Drills oi" the character shown aie usually provided with means for pressing the body against the drill and this the operator will do in order to torce the drill bit 37 against the material to be drilled.

Should the operation of the drill bit 37 stop suddenly while the switch S is closed, the tendency will be for the drilling mechaiiism M to rotate relative to the drill bit 37 about the axis of the drill bit and in the direction indicated by the arrow. This will instantly cause a pull upon the cable 19 which will operate the carbons 14 and 29 and thereby open the circuit and instantly the mechanisin will cease functioning and the insulating plug 33 will move into an interlocked position with the member 13 through the action of the spring 34 thereby maintaining the switch in an open position.

1n order to open the switch under normal conditions while the mechanism M is in operation, it is not necessaryfor the operator to take his hand from the handle 4 in order to operate the handle 35, but by merely pulling upwardly on the handle 4 he will cause a pull upon the cable 19 which in turn will open the switch S, as already described above.

It will be apparent that a switch so combined with the mechanism M that it will open under the conditions described will be a decided advantage to the operator and be the means of preventing accident to the operator and to the mechanism.

It is quite evident that I have arranged an automatic opening mechanism in combination with an electrically operated machine whereby the current to the mechanismis automatically cut olf in case of sudden tendency for the mechanism to change its normal operating position. It is also evident that in place of using the conductor y19 as the means 'for attachment to a stationary objectthat a separate means, such as a heavy cord, could be connected to the member 13 in addition to the member 19 and the cord could have a loop formed convenient for attachment to the toot or other stationary object. i

It is also apparent that the switch S in pla-ce of being mounted in connection with the machine M might be placed convenient to the foot of the operator and held thereby and connected to the handle 4 by the cable 19 which would cause the switch to open if the handle 4 were rotated as describe I claim:

1. The combination of` a drilling machine, electrical means torotate the drill bit of the machine relative tothe machine,v handles iiXed to the machine to be gripped by an operator to hold the machine in a predetermined position, a` switch having a pair of contacts mounted on the machine and arranged to open a circuit leading to the electrical means y and means arranged to be engaged by the operators foot'at a pointremote from the machine and connected tothe switch toopen the switch ifthepdrill bit sticks and the nia-f chine is rotated counter to the drill bit.

i 2. An electric switch to control a circuit Y.

on which a machine operates Vcomprising a casing, a fixed Contact Within the casing, a

l= vmovable contact Within the casing and means i 9 to mechanically connect the movable contact to an externally fixed object remote romthe switch andmeans to secure the casing to amanuallyheldand electrically operated ina-1 t chine and so positioned that the movement of the machine about a `fixed axis of rotation and away from the fixed objectyvill causer` the fixed contact to'move relative to the movable contact and open the switch and the circuit to the machine. A

i 3. An electric switch to controlacircuit on which a `machine depends comprising a caslng, a `ixedcontact `Within the casing and means to `connect the movable Contact to an 'external remote*and'iv'fixedobyect and means to secure the casing to a manually held and electrically' operated `drilling machine and so positioned that the rotation of the machine about the drill axis from a` predetermined `position Will cause the ixedcontact to move relativeto the movablecontact'and open the vswitch and the circuit to themachine and means to automatically engage the movable contact Whenthel two :contacts are `moved Y relative-to each-other to an open position', tofmaintain the:` contacts separated and the circuit open.

Intestimony `whereof` Ilatiix'my signatnre .l

l P. CHANDLER.

"mest 

